an electrical conductor or array of conductors that radiates signal energy (transmitting) or collects signal energy (receiving); it’s a transducer between a guided electromagnetic wave e.g. in a coaxial cable, waveguide, stripline and an electromagnetic wave in free space; the reciprocity relation is valid; the antenna is a passive linear reciprocal device That part of a transmitting or receiving system that is designed to radiate or to receive electromagnetic waves.

Relationship between large subject matter areas

H01P: Waveguides; Resonators; Lines, or other Devices of the Waveguide Type

Structural details or features of antennas not dependent on electric operation and applicable to more than one type of antenna. However, structural details or features described with reference to an antenna of a particular type are classified in the group or sub-group appropriate to that type. This implies that any class under H01Q 1/00 should normally be accompanied by another class specifying the antenna type and/or working principle.

Informative references

Attention is drawn to the following places, which may be of interest for search:

Heating for removing snow or ice, for example used to blow droplets of water of the radome of a horn radiator in an earth station antenna. Cooling of T/R modules (see also H01Q 21/0025 Modular arrays).

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

Means for the lighting or illuminating of aerials, e.g. for purpose of warning

Definition statement

This subgroup covers:

Originally used for lamps on masts; now also used for a LED on an antenna of a mobile phone. See the class F21S 8/00 as lighting devices for signalling; lamps on antennas or powerlines; antenna markers.

{Pivotable antennas (mechanical movement of aerial or aerial system for changing or varying the orientation or the shape of the directional pattern H01Q 3/02 ; adjustment of angle between two radiating elements H01Q 9/12)}

Definition statement

This subgroup covers:

Using (normally) a hinge.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

Mechanical movement of aerial or aerial system for changing or varying the orientation or the shape of the directional pattern

Antenna aiming; pointing the antenna to a fixed target by mechanical movement; sometimes also called tracking, i.e. means motion given to the major lobe of an antenna with the intention that a selected moving target, e.g. satellite, be contained within the major lobe. Collimation means adjusting accurately the line of sight, 'making parallel' However, scanning (a repetitive motion given to the major lobe of an antenna) in H01Q 3/10.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

{associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems (G06K 7/00 and G06K 19/00 take precedence)}

Definition statement

This subgroup covers:

Antennas for a system of interrogator / reader which sends a unique identification (ID) to a tag which receives and sends back its stored information.

Illustrative example of subject-matter classified in this group:

References relevant to classification in this group

This subgroup does not cover:

Record carrier for use with machines and with al least a part designed to carry digital markings

Normally a radar principle including time-of-flight is used to determine the distance between the radiating antenna the liquid or other material inside a container. This is to be used for details on the radiating antenna, not on other aspects for the measurement system (see G01F 23/284).

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

Normally antenna is within the housing, but part of it can be extracted (extendable; extractable; pulled out; stored, pushed in, contained; passive, retract+). The device should be claimed/disclosed; isolated antennas in H01Q 1/08 or H01Q 1/10 (and subgroups).

{with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure}

Definition statement

This subgroup covers:

Health protection, RF exposure. Overlap in H04B: “protect user against rf exposure". This class is about measures that influence the shape of the pattern, with the aim of reducing RF exposure / absorption by the user.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use

Form of a monopole antenna that is blade-shaped for strength and low aerodynamic drag. E.g. shape of a blade or fin protruding from the surface of the aircraft affecting the aircraft aerodynamics; e.g. monopole made by flat sheet.

An antenna constructed into the surface of a mechanism, or of a vehicle, without affecting the shape of that surface. Contrast with a conformal antenna: An antenna (array) that conforms to a surface whose shape is determined by considerations other than electromagnetic; for example, aerodynamic or hydrodynamic.

Definitions: An antenna whose configuration is that of a helix (the diameter, pitch, and number of turns in relation to the wavelength provide control of the polarization state and directivity) Here: helical antennas in the normal mode that means radiation broadside to the helix with linear polarization if helix diameter is less than lambda but length is comparable to lambda; i.e. helical monopole (coiling the antenna along its length).

H01Q 11/08+: helical antennas in axial/radial mode and circular polarization as monofilar, bifilar or quadrifilar (circumference in order of lambda and axial length several times larger than lambda).

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

{reducing the reradiation of a support structure (in a parabolic reflector antenna H01Q 19/023)}

Definition statement

This subgroup covers:

Reduing the influence of currents induced by the antenna onto, e.g. A support; increasing the decoupling of a ground-plane supported antenna, where the ground plane is not a counterpoise. ideally influence should be nothing, e.g. antenna on space craft.

Frequency scanning is defined as that the direction of the radiated beam is controlled by changing the operating frequency. It is based on the fact that the phase delay through a length of transmission line changes with frequency; no phase shifters.

Frequency hopping means that the frequency of the transmitter abruptly changes (or hops) in accordance with a pseudo-random code sequence; the receiver tracks these changes.

With a phased array without phase shifters, frequency hopping will inevitably result in beam scanning.

varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Definition statement

This subgroup covers:

Scanning of a radiating beam by selecting a particular fixed beam from an available set of fixed beams.

Due to the switching, there exists only a single beam at a time. The non-selected elements are simply not used. This concept is distinctively different from having a multiple beam array antenna with a beam former for which only a specific beam port is selected. In this specific case all the active elements will radiate/receive at all times.

For example, if the direction of main radiation of two antenna elements is different, selecting one or the other element will change the direction of the beam.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture ({H01Q 3/12} , H01Q 3/22 , H01Q 3/24 take precedence; { use of steered beams for mobile service area coverage H04W 16/28})

Definition statement

This subgroup covers:

Varying the phase or amplitude:

beam can be scanned by using phase shifters to change the excitation phases of its array elements;

and forming a desired radiation pattern by amplitude control via amplifiers/attenuators.

Varying the distribution of energy across aperture:

amplitude distribution (uniform or non-uniform) over a aperture, near or on an antenna, on which it is convenient to make assumptions over the field values at external points e.g. applying amplitude taper for reducing sidelobes as Taylor or Dolph-Chebyshew distributions.

Illustrative example of subject-matter classified in this group:

References relevant to classification in this group

This subgroup does not cover:

Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an aerial or aerial system

Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an aerial or aerial system using mechanical relative movement between primary active elements and secondary devices of aerials or aerial systems

Attention is drawn to the following places, which may be of interest for search:

Use of steered beams for mobile service area coverage

H04Q7/3615

Glossary of terms

In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Beam forming

weighting and summing the elements signals

Weighting

phase and amplitude applied to the signals; changing the weighting of one element to the other changes the pattern in direction and beamwidth/ beamform

Analog beamforming (RF beamforming)

phase and/or amplitude control takes place in the RF domain

Digital beamforming

phase and/or amplitude control takes place inside a beamforming computer / processor, after having sampled the RF signals using an A/D convertor.In a digital beamforming array, the received signals are detected and digitized at the element level; the digitized signals are then processed in a digital computer to form a desired beam on transmit and/or receive; processing of the digitized signals in time and amplitude according to a software program.

{Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays (tracking G01S 3/42)}

Definition statement

This subgroup covers:

Adaptivity: automatic signal-dependent weight adjustment to reduce unwanted signals and/or emphasize the desired signal or an antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal.

Different Weight-determining Algorithms in the Adaptive Control Processor.

Applebaum-Howell circuit.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

The adaptive array algorithms should not be classified here, but belong to

In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Null steering

to control, usually electronically, the direction at which a directional null appears in the radiation pattern or directing the peak of the directivity to the direction of arrival or the location of a signal source and by directing a null point of the directivity to the direction of an incoming disturbance wave

Sidelobe canceller, sidelobe blanker: destructive interference is used for blanking a null in a pattern by subtraction of signals having identical amplitude and phase: this causes a distinct null in the pattern.

Perform beam steering in an automatic fashion by retransmitting an incoming selfphased signal in a phase conjugated manner. The received signal is then retransmitted in the direction it was originated from. Active devices can be added to enhance the return signal (that is, active retrodirective antenna system); as retro-reflector or retro-reflective transponder; Van Atta array.

Informative references

Attention is drawn to the following places, which may be of interest for search:

Optical control means beam scanning by the use of photoelectric conversion i.e. optical to microwave conversion and reverse with lasers, photodiodes and fibers as true time delay elements; photonic time shifter; electric-optical conversion elements.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

An input electrical signal is launched as acoustic signal by an input transducer. The acoustic signal undergoes a finite delay as it propagates over the medium and then reconverted to electrical signal. Surface Acoustic Wave (SAW) or Magnetostatic Wave (MSW) with YIG material as ferrimagnetic material.

Mechanical phase shifters are generally constructed in coaxial line or metallic waveguides. The insertion phase is varied by means of mechanical tuning, such as variation in the physical length or rotation-displacement of a dielectric slab inside the waveguide.

Circuit configuration whereby signal inputs are connected with antenna elements via a matrix with phase shifters and hybrid couplers; Beam Forming Matrix / Network (BFM,BFN). The inputs of the matrix are referred to beam ports, since the signal of this port corresponds to a beam direction. The BFN therefore works as a kind of Fourier transformer.

For example:

Butler -Matrix: Network with number of inputs and outputs; multibeam; beam scanning by sequentially feeding the elements with the phase increment provided by the matrix. The phase gradient over the outputs is dependent on the beam port chosen.

Blass-Matrix: a number of travelling wave feed lines are connected to a linear array; at each crossover point a small will be coupled and the path difference between the input and each element control the beam direction.

Beam forming is carried out on Intermediate Frequency (l.F.). l.F. is formed when the R.F. signal coming from the antenna elements is mixed with local oscillator to convert the R.F. down to a more convenient frequency, where, for example, accurate phase shifts are easier to be performed.

Reflective array: An antenna consisting of a feed and an array of reflecting elements arranged on a surface and adjusted so that the reflected waves from the individual elements combine to produce a prescribed secondary pattern. The reflecting elements can be waveguides containing electrical phase shifters and terminated by short circuits.

Active lens: array of active units (receive-amplify-transmit), that is transponders, in which also phase shifts can be introduced. The array behaves as a lens, and high power can be generated.

Active lens is therefore of the transmission type, whereas a reflecting array is of the reflection type.

Arrangements for simultaneous operation of aerials on two or more different wavebands, e.g. dual-band or multi-band arrangements (combinations of separate active aerial units operating in different wavebands and connected to a common feeder system H01Q 21/30)

Definition statement

This group covers:

An antenna designed to operate simultaneously, without modification, in any of a number of pre-set frequency bands.

Antennas with (inherent) broadband characteristics are classified in the antenna type, e.g. folded or loaded or extended surface monopole antennas with broadband are classified in the relevant antenna type groups.

Remark: It is sometimes difficult to draw a clear line between some of the groups, but here are some clear examples representing the underlying ideas.

Loop aerials with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Definition statement

This group covers:

An antenna whose configuration is that of a loop, bent into the shape of closed curve.

Two types:

Small loops

Circumference of the loop is small compared to lambda with constant current distribution (same value at any point) - magnetic antenna (more H-field) - max. sensitivity in the plane; nulls are perpendicular to the plane of the loop - circular (ring) with a number of windings as a solenoidal coil on a frame: multiturn loop; Alford loop antenna (see H01Q 7/08).

For improving the directivity the loop antenna is drawn into a metal tube with a gap. The gap constitutes a potential source which generates a current at the exterior side of the tube. The current generates a magnetic field around the external side of the tube (screened by the metal tubes).

Loop aerials with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop with core of ferromagnetic material

The voltage at the terminals of a small loop antenna can be increased by filling the loop with a core of permeable material. The effect of the core is to increase the magnetic flux through the area of the loop.

An integral number of lambda/2 -standing waves of current or voltage; self-resonant e.g. lambda/2-dipole; lambda/4 monopole; lambda/2 X lambda/2 -square patch. Also electrically small antennas whose dimensions are such that it can be contained within a sphere whose diameter is small compared to a wavelength at the frequency of operation.

Stacked: Two or more electromagnetically coupled patches are placed on top of one another to increase bandwidth or operating on different frequencies.

Illustrative examples of subject-matter classified in this group:

See: XP00686400,XP000457518

Folded: Folding the patch to reduce its surface cross section resp. to increase its physical length

See: XP1192752, XP6010688, US2003107518, US2002175865

If stacking leads to separate dual- or multiple resonances then also H01Q 5/20 or H01Q 5/40.

If planar parasitic elements are placed also as side elements then H01Q 19/005 too.

Special rules of classification within this group

All documents where stacked patches are used.

Synonyms and Keywords

In patent documents the following expression/words "stacked patch radiators", "driven and parasitic patch", "upper or top and lower or bottom patch" and "multilayered with upper and lower patches folded" are often used as synonyms.

{with a shorting wall or a shorting pin at one end of the element (H01Q 9/0414 takes precedence)}

Definition statement

This subgroup covers:

An inverted F antenna is essentially a shorted quarter wavelength long patch. Shorting pins/posts or vertical wall inserted where the surface currents are at a minimum maintain the antenna resonance at the same frequency as a full-size patch, thus size reduction, small size.

Planar inverted L-antenna (PILA) Planar inverted F-antenna (PIFA).

Illustrative example of subject-matter classified in this group:

See: XP1112734, XP963857.

Relationship between large subject matter areas

Inverted- L and inverted -F-antennas as wire (not-planar) are in H01Q 9/42 (monopole with folded element).

Single-fed circularly polarised (CP) patch antenna: two orthogonal modes are generated by perturbations or modifications to the standard patch geometry; that leads to circular polarisation radiation in the far field; without external network.

Illustrative example of subject-matter classified in this group:

diagonal-fed nearly square; corner-fed;

truncated-corners;

square with diagonal slot, slit or cutout;

pentagon or triangular patch;

with stubs extending from the edges or notches inserted at the edge; with loading.

See: XP740145

Circular polarised patch antennas using a single feed, single- or singly-fed.

Glossary of terms

In this subgroup, the following terms (or expressions) are used with the meaning indicated:

CP

circular polarised

RHCP

right hand circular polarized

LHCP

left hand

SFCP

singly-fed or one-point feed ,or singly fed

Synonyms and Keywords

In patent documents the following expression/words "RHCP", "right hand circular polarised" and "left hand polarised" are often used as synonyms.

Patches with means for reducing spurious modes which cause cross polarization i.e. the unwanted other polarization e.g. the orthogonal linear or circular polarization caused by a second mode resp. by orthogonal currents on the patch.

Illustrative example of subject-matter classified in this group:

Patch with plurality of parallel conductive strips; with dual-probe fed (balanced feed) or two shorting pins.

Consists of a volume of a dielectric material disposed on or close to a grounded substrate, with energy transferred by way of monopole probes inserted into the dielectric or by way of aperture feeds provided in the ground substrate. In a dielectric resonator antenna (DRA) it is the dielectric material that radiates when excited by the feed.

The resonant characteristics depend upon the shape and size of the volume of dielectric, the material >>1, the shape , size and position of the feeds thereto and also on the shape, size and position of the ground plane.

Illustrative example of subject-matter classified in this group:

See: US6198450, WO2004017461.

Quite similar modifications as for patch antennas in respect to feeding (probe-fed or slot/ aperture fed), increasing of bandwidth and tuning of resonant frequency.

with feed intermediate between the extremities of the aerial, e.g. centre-fed dipole (H01Q 9/44 takes precedence)

Definition statement

This subgroup covers:

A dipole consist of two collinear and contiguous metallic rods or tubes with the feed between or of two conical conductors, typical hollow, or of strips or triangles printed on a thin dielectric substrate: maximum radiation everywhere at right angles, zero along the length.

Sleeve-dipole antenna: An antenna surrounded in its central portion by a coaxial conducting sleeve.

with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength (resonant loop aerials H01Q 7/00)

Definition statement

This subgroup covers:

An antenna composed of two or more parallel, closely-spaced dipole antennas connected together at their ends with one of the dipole antennas fed at its center and the others short-circuited at their centers.

An antenna consisting of one or more conducting wires or tapes arranged as a spiral.

Illustrative example of subject-matter classified in this group:

Special rules of classification within this group

Spiral antennas are usually classified according to the shape of the surface to which they conform (for example. conical or planar spirals). and according to the mathematical form (for example. equiangular or archimedean).

An antenna, constructed above an imaging plane, that produces a radiation pattern approximating that of an electric dipole in the half-space above the imaging plane. The monopole requires a ground plane or counterpoise which may be the equipment enclosure. The monopole is a dipole with half of its length replaced by an “image created by an infinite (or very large) ground plane; also with base or centre loading.

Coaxial monopole antenna: An antenna comprised of an extension to the inner conductor of a coaxial line and a radiating sleeve that in effect is formed by folding back the outer conductor of the coaxial line; sleeve-monopole/sleeve stub antenna.

As series-fed or shunt-fed vertical antenna whereby the antenna is insulated from ground and whose feed line connects between ground and the lower end of the antenna or the antenna is connected directly to ground and whose feed line connects between ground and a point suitably positioned above.

Illustrative example of subject-matter classified in this group:

References relevant to classification in this subclass

This subgroup does not cover:

with counterpoise comprising elongated elements coplanar with the active element

Travelling-wave antennas means antennas whose excitation has a quasiuniform progressive phase, as the result of a single feeding wave traversing its length in one direction only. Terminated in a resistance.

Rhombic antenna: composed of long wire radiators arranged in such a manner that they form the sides of a rhombus.

V-antenna: A V-shaped arrangement of two conductors, balanced fed at the apex, with induced angle, length and apex height above the earth chosen so as to give the desired directive properties to the radiation pattern.

An antenna consisting of a single conductor or multiple conductors wound into a helical shape, whereby the helix circumference is of the order of one wavelength; radiating in axial mode i.e. along the helix axis.

monofilar, unifilar or

bifilar, quadrifilar , octofilar or multifilar also in backfire configuration

Open-ended coaxial line: current minimum and voltage maximum at the end; standing waves by superposition of running and reflected wave TEM-mode coaxial line as feeding a radiating annular slot.

Microstrip line, open-ended or with short -circuited edge.

Illustrative example of subject-matter classified in this group:

Special rules of classification within this group

A microstrip-line as open-ended or with a short-circuited edge becomes a microstrip antenna when its length is half-wave resp. quarter-wave and its width less than a wavelength, then it behaves as a half wave open-ended transmission line resonator with radiating edges.

JPO classifies this antenna type here; however we classify said type as a resonant structure in H01Q 9/0407 and subgroups.

In the form of tapered or flared slot antenna: Are a type of travelling-wave antenna where a travelling wave propagates along the surface of the antenna taper with a phase velocity less than the speed of light. Under this condition, endf ire radiation results.

Illustrative example of subject-matter classified in this group:

Synonyms and Keywords

In patent documents the following abbreviations are often used:

TSA

tapered slot antenna

In patent documents the expression/word "Vivaldi antenna" is often used with the meaning "endfire slotline".

A radiating element formed by a slot in a conducting surface; in its simplest form as thin rectangular slot having a length of lam bda/2 or lambda cut in an extended thin flat sheet of metal excited by a voltage source to the opposite edges of the slot; complementary to dipole.

Slot, usually a half-wavelength long, is cut from a large (relative to the slot length) metal plate. The center conductor of a coaxial cable is connected to one side of the slot, the outside conductor is connected to the other side of the slot; the feed-point can be off-center to provide 50- Ohm impedance.

Illustrative example of subject-matter classified in this group:

See: XP010608951.

Special rules of classification within this group

Normally speaking, a slot is a cut for which the wavelength is around half a wavelength, due to the boundary conditions of the electric field.

A notch typically has an open end, and this causes that its minimum length is around a quarter wavelength.

In the field, slit is used to denominate both types of radiators (slot and notch).

Synonyms and Keywords

In patent documents the expression/word "votch- or slit antenna" is often used with the meaning "annular - or ring slot antenna".

A cylindrical waveguide with a continuous slot in its wall; the geometry can be such it is not continuous, but curved or wave, in order to change the excitation law along the longitudinal extent of the waveguide.

An antenna that couples power in small increments per unit length, either continuously or discretely, from a travelling wave structure to free space; a guiding structure that leaks power all along its length; typically 20 times lambda; remaining power in matched load.

constituted by a dielectric or ferromagnetic rod or pipe (H01Q 13/28 takes precedence)

Definition statement

This subgroup covers:

An antenna that employs a shaped dielectric rod as the electrically significant part of a radiating element. excited by a circular or rectangular waveguide; a surface wave travels along the rod till the end where it radiates into space.

The polyrod antenna is a notable example of the dielectric rod when constructed of polystyrene. Ferrod made of ferrite material.

Lenses, reflectors and polarising devices per se or in combination with a classification in H01Q 19/00 and subgroups, H01Q 21/00 and subgroups or H01Q 25/00 and subgroups if aspects of the lens, reflector etc. per se are also relevant.

Informative references

Attention is drawn to the following places, which may be of interest for search:

Lens, electromagnetic. A three-dimensional structure, through which electromagnetic waves can pass, possessing an index of refraction that may be a function of position and a shape that is chosen so as to control the exiting aperture illumination to transform a spherical wavefront.

lens constructed of dielectrics;

of metallic or artificial dielectrics.

Examples: Wire -grid lens, that is constructed of wire grids, in which the effective index of refraction (path delay) is locally controlled by the dimensions and the spacing of the wire grid; zoned lenses, that is various portions (zones or steps) form a discontinuous surface such that a desired phase distribution of the aperture illumination is achieved.

Devices for absorbing waves radiated from an aerial; Combinations of such devices with active aerial elements or systems {(anechoic chambers G01R 29/105)}

Definition statement

This group covers:

There are absorptive and reflective absorbers. In the absorptive absorbers RF energy is transferred into heat, whereas in the reflective absorbers the incident wave directs the RF energy away from the subject to be protected.

Fresnel lens antenna. An antenna consisting of a feed and a lens, usually planar, that transmits the radiated power from the feed through the central zone and alternate Fresnel zones of the illuminating field on the lens.

An antenna consisting of a portion of a paraboloidal reflector fed with an offset horn that physically intersects the reflector, part of the wall of the horn being removed to form the antenna aperture.

The horn is usually either pyramidal or conical, with an axis perpendicular to that of the paraboloid.

Aerial arrays or systems (producing a beam the orientation or the shape of the directional pattern of which can be changed or varied H01Q 3/00; {combination of imbricated aerials or arrays operating on different wavebands H01Q 5/40;} electrically-long aerials H01Q 11/00)

Definition statement

This group covers:

An antenna comprised of a number of identical radiating elements in a regular arrangement and excited to obtain a prescribed radiation pattern.

References relevant to classification in this group

This group does not cover:

Producing a beam the orientation or the shape of the directional pattern of which can be changed or varied

Sub-arrays: In large arrays, the elements may be divided into a plurality of subarrays. The division into sub-arrays have a number of advantages, e.g. reduced number of phase shifters, but a more complex feed layout.

In this subgroup, the following terms (or expressions) are used with the meaning indicated:

Flip chip bonding method

metal bumps are formed on the surface of a chip, then the chip is faced down onto metal pads of a substrate/printed circuit board and by soldering/pressing/ thermosonic or ultrasonic bumps and pads are connected (see H01L 21/00, H01L 23/00, H01L 25/00 )

A pair of vertical antennas separated by a distance of one-half wavelength or less, and connected in phase opposition to produce a radiation pattern having the shape of the figure eight in all planes containing the centers of the two antennas.

Two vertical elements fed by 180° apart and mounted so that the system may be rotated; used for direction finding.

An antenna that is designed to have a prescribed pattern shape differing significantly from the obtained from a uniform-phase aperture of the same size. not-equally or non-equally amplitude or phase; shaped-beam antenna.

Also arrays where the elements are not located in a regular arrangement but e.g. randomly or thinned ; not-equally spaced.

Space-tapered or density-tapered array, that is an array antenna whose radiation pattern is shaped by varying the density of driven radiating elements over the array surface.

Turnstile or like aerials comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre

Definition statement

This subgroup covers:

An antenna composed of two dipole antennas, perpendicular to each other, with their axes intersecting at their midpoints. Usually, the currents on the two dipole antennas are equal and in phase quadrature.

Form of a signal processing antenna system having circuit elements associated with its radiating element(s) that perform functions such as multiplication, storage, correlation, and time modulation of the input signals

Aerials or aerial systems providing at least two radiating patterns (arrangements for changing or varying the orientation or the shape of the directional pattern H01Q 3/00)

Definition statement

This group covers:

An antenna capable of creating a family of major lobes from a single non-moving aperture, through use of a multiport feed, with one-to-one correspondence between input ports and member lobes, the latter characterized by having unique main beam pointing directions.

Often, the multiple main beam angular positions are arranged to provide complete coverage of a solid angle region of space.

Illustrative example of subject-matter classified in this group:

Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangements for changing or varying the orientation or the shape of the directional pattern

Sum pattern: a radiation pattern characterized by a single main lobe whose cross section is essentially elliptical, and a family of side lobes the latter usually at a relatively low level.

Difference pattern: a radiation pattern characterized by a pair of main lobes of opposite phase, separated by a single null, plus a family of side lobes, the latter usually desired to be at a low level.

Antennas used in many radar applications are capable of producing a sum pattern and two orthogonal difference patterns, the difference pattern can be employed to determine the position of a target in a rightlleft and up/down sense by the antenna pointing, which places the target in the null between the twin lobes of each difference pattern.

Radar system is called monopulse radar system because direction-finding information is obtainable from a single pulse A monopulse receiving system includes a monopulse circuit which receives signals from the antenna and forms sum and difference monopulse output signals. The sum and difference signals are formed by combining received antenna signals in a particular manner. The signals can be combined using circuits referred to as hybrid circuits. The monopulse sum and difference signals can be formed either at the transmitted signal frequency or, after down conversion of a return signal, at a lower frequency.